Garage Door Insulation: The Ultimate Guide


Depending on where you live, the temperature in your garage can be unbearable. In winter, it can easily fall to below freezing, while summers in the south can push the temperatures over 100 degrees.

A good place to start is with the biggest non-insulated surface in your home: your garage door.

By itself, insulation won’t make your garage warm and toasty.

However, adding a garage door insulation kit is one of the most effective (and inexpensive) ways to get a few more months of comfortable use out of your garage.

I’ve compiled a list of the three best garage door insulation kits available today. Plus, you’ll also find a quick guide on the different types of insulation and which ones make sense for your garage.


Why Should You Insulate Your Garage Door?

Your garage door is the single biggest non-insulated surface in our home. If you have an attached garage there’s nothing but a thin layer of metal between your home and the outside.

So if you think that thin metal door is enough, then I want you to try something.

Put your bare hand on the inside of your garage door in the middle of a hot summer day or a cold day in the winter.

Ouch.

Adding just a small amount of insulation can make a big difference in the inside temperature.

You can add insulation to both new and existing garage doors. Garage door insulation kits made of foam or reflective barriers can easily be added to existing doors. These kits usually have an R-value of between R-2 and R-8. For better results, you can opt to replace your old garage door with a brand new insulated garage doors. New insulated garage doors have R-values from R-6 to R-19.

When you combine garage door insulation with other insulation methods like weatherstripping and insulating other areas of your garage, you can actually increase the inside temperature of your garage by 10 or even 12 degrees in the winter. 

This will in effect address the “weakest link” of the insulation process (your garage door), improving your garage’s indoor temperature overall. 

Benefits of Garage Door Insulation

As I mentioned above, an insulated garage door will keep your indoor garage space warmer in the winter, cooler in the summer. It also helps keep pesky visitors out (the vermin kind not human).

However, these are far from the only benefits derived from the process. You will also effectively:

  • Save Energy Costs: If you live in a warmer climate, this might not be a factor as much as it would in the northern states. However, in general, you can save around 12% on your total energy costs by installing insulation to your garage door. 
  • Increase Your Property Value: Since garage door insulation will save you money in energy costs, it can also increase your overall property value. According to a Remodeling Value Report issued in 2019, you would recoup some 95.2% of your investment when selling your home. (East North Central Region of America numbers). Again, if you live in a warmer climate like I do, you might not enjoy as much of a benefit from insulation as other parts of the country. However, it will help when it comes time to place your home on the market nonetheless. 
  • Cuts Down on the Noise: If your garage track system is anything but quiet, insulation can help reduce the grinding noise you hear when your door moves. It can also help dampen the vibration sounds your door makes as it raises and lowers. Not to mention the fact that it will reduce the sound from down the street when your neighbors are hosting yet another soiree. The point is, it helps keep outside noises out or inside noises in, which might be a factor if you have grumpy or loud neighbors. 

How Hot (or Cold) Can Your Garage Get?

Most people reading this are going to try to keep their garage comfortable in the winter months.

It’s never going to snow inside your garage, but a non-insulated garage can still get temperatures below freezing if its cold enough outside. This can cause the water in pipes and hoses to freeze, causing damage to equipment like your water heater or a garage refrigerator.

I’ve got the opposite problem in Florida.

My garage faces south, so the hot sun is beating down on my metal garage door. Essentially my garage becomes a microwave in the summer.

The temperatures inside the garage are regularly up to 20 degrees hotter than they are outside. 90 degree temperatures outside mean my garage is pushing 110 degrees.

What’s worse is that my master bedroom is directly above the garage. The warmer my garage gets, the warmer my bedroom gets. That means my fans and air conditioner have to work harder to cool down my house.


What’s a Good R-Value for a Garage Door?

When you’re talking about insulation, the most important metric that you’ll be looking at is the R-Value.

The construction industry in the United States uses a metric called an R-Value as scoring system for how well a material resists the conductive flow of heat.

I go into more depth in this article, but a good R-value for a garage door is around R-6 for detached garages, R-9 for garages that aren’t actively heated or cooled, and R-13 or higher for garages that are actively heated or cooled.

If you’re adding insulation to your existing garage door, a good range is between R-4 and R-8.

The higher the R-Value, the better protection against conductive heat.

But there’s a catch.

I mean…of course there is, right?

There are diminishing returns as the values increase. An R-value of 16 is not twice as good as an R-Value of 8. In fact, it’s only about five percentage points more effective.

So don’t base your purchase completely on the R-Value. It’s an important factor, sure. But it’s not the only one.

source: amarr.com

What Kind of Insulation Works Best for Garage Doors?

There are three main types of garage door insulation: rigid foam, fiberglass and radiant barriers. I’ll go into some high-level basics on each.

Rigid Foam

Most garage door insulation kits will use some type of rigid foam insulation. It’s very affordable and easy to install in most garage doors.

There are three main types of rigid foam insulation that you could use.

I’ll highlight each of them here, but don’t worry. I won’t get into the science of how they’re constructed.

  • Expanded Polystyrene (EPS): This is the most common form of insulation that you’ll find in garage door insulation kits. EPS has an R-Value of between 3 and 4.
  • Extruded Polystyrene (XPS): XPS is between 10% and 30% more expensive, but more rigid and won’t absorb water as quickly. It has an R-Value of around 5.
  • Polyisocyanurate (polyiso): This has an R-Value of just under 7, but it’s also the most expensive rigid foam insulation.

The relatively light weight of rigid foam insulation makes it ideal for most residential garage door applications.

Fiberglass

Fiberglass insulation is very common in homes, but not in garage door insulation kits.

Owens Corning, the Pink Panther company, is the only company I know of to make a fiberglass insulation kit specifically for your garage door. It has a slightly higher R-value on average (R-8) and can easily conform around door hardware.

After a lot of research, I would not recommend fiberglass insulation on a garage door.

  1. Fiberglass insulation is heavier than rigid foam – almost 50% heavier. That extra weight can put a strain on your garage door opener’s motor, not to mention the torsion springs used to raise and lower the door. If the door is too heavy, you’ll end up shortening the lifespan of the garage door opener.
  2. Fiberglass insulation loses its effectiveness when it gets wet. This is the deal breaker for most of the country. A little water damage is OK. They insulation will bounce back as it dries out. If it stays wet too long, the fiberglass may become cemented together and it’ll be completely useless.

Radiant Barriers

Radiant barriers are the least expensive form of garage door insulation, costing about half that of foam kits.

If you’ve walked through the insulation aisle of your local Lowe’s or Home Depot, you’ve probably seen these rolls of reflective foil that look like something straight out of NASA.

That’s not too far off actually.

They’re called radiant barriers and what they do is reflect heat waves back on the source. It’s a similar concept to the heat shields on the bottom of the Space Shuttle that reflect the extreme atmospheric heat away from the spacecraft.

I’ll bring it a bit closer to home for you.

Have you ever stood next to your garage door (or anything else super-hot) and felt the heat without even touching the surface? That’s the heat waves radiating off the surface of the door.

Radiant Barriers don’t have much in the way of an R-value. That’s not really how they work. Remember, R-values measure resistance to conductive heat (touching the surface). Radiant barriers are great at reflecting heat waves back, but they can’t stop temperature increases from the hot (or cold) air all around your garage door.

One big catch (I know, again with the catches) is that radiant barriers need an air cavity next to their reflective side. If you glue the reflective foil right up against the metal of your garage door, it loses effectiveness.

Other Insulation Types (That You Won’t Find on Garage Doors)

It’s worth noting there are some popular types of insulation that you won’t see on garage door insulation kits.

Cellulose insulation is made out of completely organic material like plant fibers, cotton or even recycled newspapers. It’s very similar to fiberglass insulation in terms of performance. However, its much more costly so it hasn’t caught on yet.

Spray foam insulation is used in many residential applications. In fact, my house has spray foam insulation in most of the walls. Spraying the foam allows it to reach into any gaps between wall-studs and eliminate any drafts. However, it’s not well suited for garage doors.

Which Type of Insulation is Best?

The best of both worlds approach would be to use a radiant barrier in conjunction with a foam or fiberglass insulation, so their benefits stack.


Time For a New Insulated Garage Door?

If you aren’t sure your old garage door can take the added weight of insulation or you just don’t want to fool with the process, you might instead prefer buying a new garage door that is already optimally insulated. 

According to Realtor.com, replacing your garage door is the single best investment you can make when remodeling your house. A whopping 98% of the cost of a new garage door is recouped when its time to sell – especially if it is insulated!

Plus, you get to shave money off your monthly heating and cooling bills while you own the home.

A brand new insulated garage door has an R-value between 6 and 19, depending on the manufacturer. One thing to keep in mind that windows, while they make the door look cool, they certainly aren’t cool – at least not in the summer. The door may have heavy duty insulation, but any glass windows would let the sun and heat right though.


What to Look For When Buying a New Insulated Garage Door

You have three main options in terms of insulation in new garage doors.

They include a single-layer, no added insulation beyond the door materials itself (doesn’t help you much), the double-layer door, with one added layer of insulation often this is polystyrene, or a triple-layer door, with a thicker layer of either polyurethane or polystyrene insulation.

Of course, the triple-layer is the most energy-efficient and ideal for any areas of extreme temperatures i.e. very hot or very cold climates.

The following is a breakdown of the type of material used in modern garage doors. Look them over to better understand what to look for when shopping for your new door:

  • Steel: The most commonly used material in garage doors is steel. This is because it has low maintenance demands, is durable and comes in a wide range of design options so you are sure to find one that fits your current home’s style. It also provides a good amount of insulation. 
  • Wood: While the wood itself doesn’t offer much in terms of insulation, many opt for wood garage doors, especially in colder climates as outlined above. This will require you to add insulation, though, which doesn’t really help you in this situation. 
  • Composite Wood: Similar to real wood, composite wood doesn’t on its own provide much in the way of insulation. However, you can choose to layer composite wood over steel to create a double or triple layer garage door, which will provide the energy efficiency of a practical steel door with the classic appearance of wood. 
  • Aluminum: While aluminum is lighter than steel and provides a good alternative, it doesn’t provide much insulation. 

Things to Consider Before You Buy a New Garage Door

If you’re in the market for a new garage door, or if you live in an extreme environment (I’m looking at you Arizona), then a brand new insulated door really is a must.

It’s not going to make it cool and cozy in your garage if the outside temperature is hitting 120 degrees, but an insulated garage door will cut about 20 degrees off the temperature inside.

That can be the difference between uncomfortable and downright dangerous temperatures.

However, buying a new garage door isn’t necessarily for everyone. It’s not cheap. Estimate about $3K for a quality door once you factor installation costs. Even if you do it yourself, you’re still going to be in the two-thousand dollar range.

That’s a lot of money.

So I wanted to see if there were other options.


What About Garage Door Insulation Kits?

Several companies make garage door insulation kits, which are basically just pre-cut sections of foam insulation that slide into channels on your existing door. There are also reflective foil wrappings (called radiant barriers) that promise to do the same thing.

Obviously a $100 garage door insulation kit isn’t going to be as effective as a $3000 insulated garage door.

But is it good enough for most people?

To help answer that, I’ve compiled a list of the best garage door insulation kits for every budget. One of these will help make your garage more comfortable, no matter what the outside weather is like.


The Best Garage Door Insulation Kits


Matador

Matador is easily my choice for the best garage door insulation kit and it’s the one I have in my own garage. You can see my thoughts and how I installed it here.

It’s made of a thick polystyrene foam that fits neatly in between the frame of pan-style garage doors. That’s the style of garage doors that that have a thin layer of steel and support rails going along the inside of the door.

Even if you don’t have a a pan-style garage door, the Matador kit should still fit. I’ve got a “sandwich style” garage door, which is a little thicker, and I was able to cut the Matador foam panels to fit and use some foam adhesive to get a nice solid fit.

Overall, I’m thrilled with the Matador kit. That added insulation helps lower the temperature in my garage during the day by around 10 degrees on the hottest days.

Pros

Cons

  • R-Value of 4.8
  • Polystyrene laminate panels for durability and soundproofing
  • Snap-in installation for many garage door types
  • Large garage doors need two kits
  • May need to adjust torsion spring because of the additional weight
Matador Garage Door Insulation Kit
$143.68
Buy on Amazon
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09/28/2021 04:56 am GMT

Owens Corning

The Owens Corning garage door insulation kit uses actual fiberglass insulation, which gives it the highest R-value that I’ve found!

The fiberglass panels conform directly to the door itself, which makes them incredibly dent resistant. So if you’ve got an environment inside your garage where things can bump into your garage door, this adds an extra layer of protection. I was always the kid that shot hockey pucks and tennis balls against the garage door, so my parents definitely could have used this when I was growing up.

In addition to having the best R-value for any garage door insulation kit that I’ve found, the fiberglass panels are also really noise resistant. Owens Corning estimates that it could reduce noise by up to 20% over an un-insulated door.

Because the panels conform to the door itself, it will only work where there’s a frame on the inside of the door. While that’s common in pan-style doors, it’s not common in other door types. So this may not be the right solution, depending on what type of garage door you have.

Since the insulation snaps onto the door with plastic clips, many homeowners say that they need to use Gorilla Tape or other adhesive to clean up the edges.

Pros

Cons

  • R-Value of 8.0
  • Up to 20% noise reduction
  • Only need common tools to install
  • Only works on pan-style doors
  • Many users recommend Gorilla Tape to seal the edges

Reach Barrier 3009

The final entry on this list of the best garage door insulation kits is the Reach Barrier 3009. Unlike the Matador and Owens Corning insulation kits, the Reach Barrier kit is a radiant barrier. As such, it has no R-value, but that doesn’t mean that it’s not effective!

Unlike standard insulation, a radiant barrier works by reflecting the heat (or cold) back on its source. In a cold climate, the best insulation is a combination of fiberglass or foam panels to absorb the cold from the outside air, and a radiant barrier to reflect the heat from your garage back in on itself to help keep you warmer.

The Reach Barrier insulation kit does just that. The reflective metallic sides sandwich a bubble-wrap type of inner layer that helps reduce noise and provide a little extra durability.

Installation is easy, with double-sided adhesive tape. Simply measure and cut to fit your door.

I look at the Reach Barrier (or any radiant barrier insulation) as an “finishing touch” to insulating your garage. It works best in conjunction with another type of insulation or to reflect the heat from a garage heater back into your garage so it doesn’t escape through the door.

Pros

Cons

  • Cheapest insulation solution
  • Very lightweight
  • Works best in conjunction with other insulation
Reach Barrier Garage Door Insulation Kit
$40.13
Buy on Amazon
We earn a commission if you click this link and make a purchase at no additional cost to you.
09/28/2021 03:36 am GMT

FAQ

How Much Will it Cost to Insulate My Garage Door?

It depends which way you want to go, to be honest.

A brand new insulated garage door will set you back between $2,000 – $3,000 by the time you get it installed. By contrast, adding a garage door insulation kit will only set you back around $200 for a kit, or about $50 and an afternoon’s work if you go DIY.

To me, the choice is clear. Unless you’re already in the market for a brand new garage door, go for one of the garage door insulation kits (or the DIY version).

Adding it to your existing door may do enough to make your garage more comfortable during the cold winter or hot summer months.

If it doesn’t work as well as you wanted then you can still buy a new garage door down the road. However, you’ve bought yourself a little extra time to try to find a good deal.

Are There Types of Garage Insulation That Work Better in Warm vs Cold Climates?

Yes, there are some types of garage doors and/or insulation that work best in hot and cold climates respectively.

In general, if you are trying to keep hot air out and cold air in, a convex foam board with reflective foil is a good option.

If you live in a northern climate and want to keep the cold out and warm in, avoid metal doors. Metal doors are great conductors of heat and will steal the heat you have inside and pull it outside.

Instead, your best option could be thermal insulation on a wooden door. You can also install foil sheets on your garage windows to pull heat into your garage.

It’s most important for your northern readers to seal all those cracks and crevices in and around your garage with weather-resistant stripping, along with adding thermal insulation to your garage door itself. 

Is There Any Reason to Avoid Garage Insulation?

After reading all this, you’re probably wondering if there’s any reason NOT to insulate your garage door.

In short, yes, there are a few things to consider. You should always consider the added weight insulation will have on your garage door.

For some garage doors, this is no issue at all, for others, it can cause significant problems. If your garage has little margin for error in terms of the weight it can handle, adding the weight of insulation can eventually cause the springs to break.

In this case, or if your garage door is older and wearing out, you might be better off purchasing a new one that is better insulated from the start.  

However, don’t misunderstand, I am all for insulating your garage door.

When it’s done right and the garage door still functions as designed, it will not be inhibited and it shouldn’t cause any issues. If you aren’t sure your door can take the added insulation, do a test run by installing insulation in just one area of the door.

Watch for signs of issues and if none are noted, you can likely add insulation to the rest of the door without fear. 

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